Improvement in compositions for slates



1 NITED STATES PATENT OFFICE.

GEORGE W. M. BOOKWALTER, OF WINCHESTER, OHIO.

IMPROVEMENT IN COMPOSITIONS FOR SLATES, &c.

Specification forming part of Letters Patent N0. 148,170, dated March 3,1874; application filed November 6, 1873.

To all whom it may concern Be it known that I, GEORGE W. M. Boon-WALTER, of Winchester, in the county of Preble and State of Ohio, haveinvented certain new and useful Improvements in Liquid Slating forBlackboards, Bulletin-Boards, 850.; and do hereby declare that thefollowing is a full, clear, and exact description thereof.

My invention consists in the composition for slate, consisting of theingredients hereinafter mentioned, for the purposes set forth; and toenable others skilled in the art to avail themselves ot' the benefits ofit, I will now proceed to describe it.

1 take two. (2) parts leveling-varnish to four (4) parts spiritsturpentine; three (3) parts pumice-stone; Englishfilling, one (1) part 5lamp or bone black, two (2) parts; manganese, (or black oxide,) in theproportion of six (6) ounces to every gallon; and a sufficient quantityof Prussian blue to impart to the mixture a slate color or hue-as ageneral rule, four (4) ounces per gallon. I then place the aforesaidingredients in an ordinary paint-mill, and grind them as paint is.ground. The compound is then ready to be applied to the wall or othersurface with a flat camel or sable hair brush.

The compound can be used of such consistency as to be applied eitherwith a brush or trowel. The surface will be very hard and durable, notliable to be affected by the weather, water, or grease, making itpeculiarly adapted to bulletin-boards and blackboards for schoolrooms,from the fact that the figures or writing can be seen at any angle. I

I- would here remark that English filling is a powder manufactured inEngland, well known to the trade, and is used by coachmakers for thepurpose of filling up or getting a smooth surface on the bodies ofcarriages.

Having thus fully set forth the nature of my invention, its mode ofpreparation, and application, what I claim, and desire to secure byLetters Patent, is-

The composition for slates of the withinnamed ingredients, in about theproportions named, substantially as and for the purposes set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

GEORGE W. M. BOOKWALTER.

Witnesses JAMES RUssELL, (l. U. FETHERLING.

